Pathophysiology and 3 Patterns of Health Books/Medical Surg… · UNIT3 Pathophysiology and Patterns of Health CHAPTER 8 Genetic Implications of Adult Health Nursing CHAPTER 9 Nursing

UNIT

3Pathophysiology andPatterns of Health

CHAPTER 8Genetic Implications of Adult HealthNursing

CHAPTER 9Nursing Care of Clients Experiencing Pain

CHAPTER 10Nursing Care of Clients with Altered Fluid,Electrolyte, and Acid–Base Balance

CHAPTER 11Nursing Care of Clients ExperiencingTrauma and Shock

CHAPTER 12Nursing Care of Clients with Infections

CHAPTER 13Nursing Care of Clients with AlteredImmunity

CHAPTER 14Nursing Care of Clients with Cancer

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Genetic Implicationsof Adult HealthNursing

■ Integrate genetic physical assessment and the use of a pedigreefamily history into delivery of nursing care.

■ Identify clients or families with actual or potential genetic condi-tions and initiate referrals to a genetics professional.

■ Prepare clients and their families for a genetic evaluation and fa-cilitate the genetic counseling process.

■ Integrate basic genetic concepts into client and family educationand the reinforcement of information provided to clients by genetic professionals.

CHAPTER

8LEARNING OUTCOMES

■ Discuss the role of genetic concepts in health promotion andhealth maintenance.

■ Apply knowledge of the principles of genetic transmission andrisk factors for genetic disorders.

■ Describe the significance of delivering genetic education andcounseling follow-up in a professional manner.

■ Identify the implications of genetic advances on the role of nurseswith particular attention to spiritual, cultural, ethical, legal, and social issues.

■ Identify the significance of recent advances in human geneticsand the impact on healthcare delivery.

CLINICAL COMPETENCIES

Resources for this chapter can be found on the Prentice Hall Nursing MediaLink DVD-ROMaccompanying this textbook, and on the Companion Website athttp://www.prenhall.com/lemone

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homozygous, 151human genome, 148meiosis, 150mitochondria, 151mitosis, 149monosomy, 150multifactorial conditions, 155nondisjunction, 150penetrance, 155phenotype, 151

polymorphisms, 152sex chromosomes, 149somatic cell, 149test sensitivity, 157test specificity, 157translocation, 151trisomy 21, 150wild-type gene, 152X-linked dominant, 152X-linked recessive, 152

alleles, 151autosomes, 149carriers, 153chromosomes, 149DNA-based tests, 157gene, 151gene expression, 155genetic locus, 151genotype, 151heterozygous, 151homologous chromosomes, 149

KEY TERMS

The genetic knowledge obtained from the Human GenomeProject (Box 8–1) has changed not only the way disease treat-ment is approached but, more importantly, how nurses look athealth promotion and health maintenance. DNA is at the centerof the state of our health (Figure 8–1 ■). We now know thatgood health is associated with genes functioning properly andif genes are not functioning properly, disease or an increasedrisk for disease can result. This includes not only the traditionalgenetic disorders, but also common complex diseases such asheart disease, stroke, diabetes, and several kinds of cancer. Theknowledge gained from human genome research has and willhave a profound impact on the prevention, diagnosis, and treat-ment of genetic disorders and complex diseases.

INTEGRATING GENETICS INTONURSING PRACTICEGenetic knowledge will continue to revolutionize how personsperceive themselves as well as their health status and theirhealth potential. Therefore, nurses must integrate new geneticknowledge into their nursing practice. This expectation hasbeen defined in the ANA/ISONG Statement on the Scope andStandards of Genetics Clinical Nursing Practice (Box 8–2). Inaddition, a national interdisciplinary group known as the Na-tional Coalition for Health Professional Education in Genetics(NCHPEG) has developed competencies to encourage health-

BOX 8–1 Human Genome Project

In 1986, the U.S. Department of Energy (USDOE) announced theHuman Genome initiative, and in 1990 the USDOE joined withthe National Institutes of Health (NIH) to develop the HumanGenome Project (HGP). The ultimate goal was to sequence thehuman genome and to identify all human genes. The completionof a high-quality reference sequence was announced in April2003. Information obtained through the sequencing of the hu-man genome has had a tremendous impact on finding the genesassociated with human disease. Future research will now be di-rected toward understanding the complex functions of cellularregulation, human variation, and the interplay of genes and envi-ronment and how all the cell organelles, genes, and proteins worktogether in life’s functions (USDOE Genome Programs, 2003).

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DNAthe molecule of life

Trillions of cells

Each cell:• 46 human chromosomes• 2 meters of DNA• 3 billion DNA subunits (the bases: A, T, C, G)• 25,000 genes code for proteins that perform all life functions

Protein

Figure 8–1 ■ Each cell nucleus throughout the body containsthe genes, DNA, and chromosomes that make up the majority of anindividual’s genome. The remaining portion of the human genomeis in the mitochondria.

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CHAPTER 8 / Genetic Implications of Adult Health Nursing 149

care providers to integrate genetic knowledge, skills, and atti-tudes while delivering care to clients.

Nurses must have basic genetic knowledge to care for theneeds of clients and their families with known or suspected ge-netic disease. Basic level nursing practice that meets the stan-dard of genetic nursing includes:■ Identifying simple risk factors by completing a genetics focused

family history and also drawing a three-generation pedigree■ Incorporating a genetics focus into physical assessments■ Applying concepts of health promotion and health mainte-

nance to assist the client and family to make informed deci-sions and lifestyle choices

■ Collaborating with the client to perform interventions that in-clude advocacy, supporting the client’s decisions, teaching,making referrals, clarifying information, and providing in-formation about available resources and services

■ Partnering with the community to educate the public andsupporting legislation that protects genetic information andthose with genetic conditions from discrimination

■ Completing an evaluation of the delivery of care for the client■ Applying knowledge of the ethical, legal, and social impli-

cations of genetic information.Through the application of fundamental genetic concepts,

nurses can significantly improve the nursing care provided toclients.

GENETIC BASICSA basic knowledge of the cell, DNA, cell division, chromo-somes, and genes is essential to deliver the genetic standard ofcare to the adult client (Box 8–3).

The cell is the basic unit of life and it is the working unit ofall living systems. Life starts as a single cell, but the developedhuman body is made up of trillions of cells. These cells sharecommon features such as a nucleus that contains 46 chromo-somes, and organelles such as mitochondria. There are manydifferent types of “specialized” cells that function differentlydepending on their location. For example, pancreatic cells havea very different function than that of nerve cells.

All human cells, except mature red blood cells, contain acomplete set of deoxyribonucleic acid (DNA) molecules. DNAmolecules consist of long sequences of nucleotides or basesrepresented by the letters A, G, T, and C. The order of thesebases gives the exact instructions for the functioning of thatparticular cell. Writing the correct order of the bases using theabove abbreviations represents the sequence of the bases inDNA. All of the DNA in a human cell is referred to as the human genome, or the complete set of inheritance for an indi-vidual. The human genome includes the DNA in the cell nu-cleus as well as the DNA found in the mitochondria, which willbe discussed later in this section. Each person’s genome isunique. Identical (monozygotic) twins are the exception be-cause they develop from only one fertilized ovum and shareidentical DNA (Guttmacher & Collins, 2002).

The cell nucleus contains about 6 feet of DNA that is tightlywound and packaged into 23 pairs of chromosomes making acomplete set of 46 chromosomes. The structure and number ofchromosomes can be shown by a karyotype, or picture, of an in-dividual’s chromosomes (Figure 8–2 ■) There are two copies ofeach chromosome. One copy, or half of the complete set of these46 chromosomes, is inherited from the mother and the other copy,or the other half of the 46 chromosomes, is inherited from the fa-ther. For example, an individual will have two of chromosome 1,one inherited from her mother and one inherited from her father.These two copies or pairs of inherited chromosomes are calledhomologous chromosomes. Chromosomes are numbered ac-cording to size, with chromosome 1 being the largest and chro-mosome 22 being the smallest. The first 22 pairs ofchromosomes, known as autosomes, are alike in males and fe-males. The 23rd pair, the sex chromosomes, determines an indi-vidual’s gender. A female has two copies of the X chromosomes(one copy inherited from each parent) and a male has one X chro-mosome (inherited from his mother) and a Y chromosome (in-herited from his father).

Cell DivisionMitosis and meiosis are the two types of cell division in humancells. Mitosis is the process of making new cells and it takesplace in the somatic, or tissue, cells of the body. Cell divisionthrough mitosis heals wounds and replaces cells lost daily onskin surfaces and in the lining of gastrointestinal and respiratory

BOX 8–2 ANA/ISONG Standards of GeneticsClinical Nursing Practice Statement

ANA/ISONG Statement on the Scope and Standards of GeneticsClinical Nursing Practice:

All licensed registered nurses, regardless of their practicesetting, have a role in the delivery of genetics services andthe management of genetic information. Nurses requiregenetic knowledge to identify, refer, support, and care forpersons affected by, or at risk for manifesting or transmitting,genetic conditions. As the public becomes more aware of thegenetic contribution to health and disease, nurses in all areasof practice will be increasingly asked to address basicgenetics-related questions, service needs, or both.

Source: Used with permission from American Nurses Association andInternational Society of Nurses in Genetics. Copyright 1998, p. 2. Washington,DC: American Nurses Publishing.

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BOX 8–3 Using the People-First Approach

The nurse must incorporate a “people-first” philosophy and use genetic terminology that is sensitive to the maintenance of an in-dividual’s positive self-image. This can be accomplished by using“unaltered” or “wild-type” gene instead of “normal” gene and “al-tered” gene; “altered, disease-producing gene” or “gene alteration,”instead of the term “mutated” or “abnormal” gene when commu-nicating genetic concerns to clients, other healthcare providers, orthe public.

wild type � normal � expected � unalteredversus

mutated � abnormal � defective � unexpected � altered

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150 UNIT 3 / Pathophysiology and Patterns of Health

tracts. In addition, mitosis is responsible for development. Themitotic activity of the zygote and its daughter cells is the foun-dation for a human’s growth and development. The zygote un-dergoes mitosis to form a multicellular embryo, then fetus, theninfant. Cell division through mitosis results in two cells calleddaughter cells that are genetically identical to the original cell, ormother cell, and each other.

Meiosis is also known as the reduction division of the cell.Meiosis occurs only in the sex cells of the testes and ovariesand results in the formation of the sperm and oocyte (gametes).Meiosis is very similar to mitosis in that it is a form of cell di-vision; however, through a series of complex mechanisms, theamount of genetic material is reduced in half (23 chromo-somes). This is very important because when the two sex cellscombine during fertilization, the total number of chromosomes(46) is present in the offspring’s cells. The purposes of meiosisis to produce gametes, to reduce the number of chromosomesby half, and also to make new combinations of genetic materialfrom crossing over and independent assortment processes,which allows diversity in the human population.

Chromosomal AlterationsAlterations in chromosomes often occur during cell division(meiosis or mitosis) and are classified as either alterations inthe number of chromosomes or structural alterations. They in-volve either part of or the whole chromosome. The clinical con-sequences of number and structural changes in thechromosomes in an individual vary depending on the amountand type of DNA affected by the alterations.

Alterations in Chromosome NumberAn increase or decrease in chromosomal numbers can occur dur-ing meiosis or mitosis (Box 8–4). Alterations occur often duringmeiosis because meiosis is a highly specific and complex processand each new daughter cell must contain exactly one chromosomefrom each homologous pair of chromosomes. During meiosis, thepaired chromosomes may fail to separate, resulting in daughtercells with either two copies or no copies of that chromosome. This

is known as nondisjunction. This creates an egg or sperm cellwith either two copies or no copies of a particular chromosome.When these egg or sperm cells are fertilized by a normal gametethat contains 23 copies of all of the chromosomes, a zygote that ismonosomic (one member of the chromosome pair is missing) ortrisomic (having three chromosomes instead of the usual two) re-sults. These circumstances produce such conditions as Turner syn-drome (monosomy) or trisomy 21 (Down syndrome).

Alterations in Chromosome StructureAlterations in chromosome structure include inversions, dele-tions and duplications, and translocations. In a chromosomalinversion a segment of a chromosome is reversed, changing theDNA sequence for that portion of the chromosome. It occurswhen a chromosome breaks in two places and the piece be-tween the breaks turns upside down and reattaches within thesame chromosome. The clinical consequences of an inversiondepend on how much chromosomal material is involved, wherethe inversion occurs, and what type of inversion is present.

A chromosomal alteration that includes a missing (deletion)or additional (duplication) whole chromosome or segment of a

Figure 8–2 ■ A karyotype is a picture of an individual’s chromosomes. It shows the chromosomal structure and number of the 22 pairsof autosomes and the sex chromosomes.

BOX 8–4 Variations in Chromosomal Number

Aneuploidy—the condition when extra or missing chromosomesexist; if there is an addition or deletion of chromosomenumber and the individual lives, physical abnormalities and/ormental retardation is common.Monosomy—the loss of a single chromosome from a pair; i.e.,

Turner syndrome (45,XO)Trisomy—the gain of a single chromosome, making a total of

three copies of a certain chromosome; i.e., trisomy 21 orDown syndrome

Euploidy—the presence of the normal number of 46chromosomes

Polyploidy—the condition when more than two pairs of all thechromosomes are present

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chromosome is an unbalanced rearrangement. An unbalancedrearrangement can result in missing genes, confusing direc-tions from the genes, or too much gene product, which often re-sults in a condition that is not compatible with life or alteredphysical and/or mental development. An example is cri du chatsyndrome (mental retardation, crying that sounds like a catmewing, and low-set ears), which results from a large deletionon chromosome 5.

Translocation (chromosomal reshuffling) occurs when asegment of a chromosome transfers or moves and attaches it-self to another chromosome. An example is the reciprocaltranslocation that is found in 95% of clients with chronic myel-ogenous leukemia (CML). The contributing translocation oc-curs between chromosomes 9 and 22 and is known as thePhiladelphia chromosome (Ph 1). Unlike the translocation re-sponsible for Down syndrome, which occurs in the germ cells,the translocation responsible for CML occurs in somatic cellsand therefore is not inheritable (National Cancer Institute,2005; Nussbaum et al., 2001).

GenesThe nurse must also have knowledge of genes—what they are,the role genes play in homeostasis, as well as the consequencesof gene alterations. How these gene alterations are inherited isalso important for nursing interventions and teaching the clientwho is at risk for or who has a known gene (DNA-based) con-dition. Knowledge of the function and inheritance of genes isimplicit in health promotion as well as health maintenance ofthe client and his or her family.

A gene is a small portion (segment) of the nucleotide(base) sequence of a chromosome DNA molecule that can beidentified as having a particular function or characteristic.These segments of DNA within each gene have specific di-rections for the functioning of the gene. This specific se-quence of nucleotides (the genes and the variations therein) isreferred to as the individual’s genotype. Each chromosomecontains numerous genes arranged in a linear order. Re-searchers currently believe there are about 20,000 to 25,000genes in the human genome. The number of genes present oneach chromosome varies. Chromosome 1 is the largest chro-mosome and has the largest number of genes with 2,968. TheY chromosome has the smallest number of genes with 231(Human Genome Project [HGP], 2004a).

All genes come in pairs because chromosomes come inpairs. The only exception to all genes being paired are thegenes on the sex chromosomes (X and Y) present in males.All genes have a specific location on a specific chromosome.This is known as the genetic locus. For example, one of themany genes located on chromosome 19 is a gene for eyecolor. There may be slight variations or different forms of agene, for instance, green versus blue eye color, and these dif-ferent forms or versions of genes are called alleles. When anindividual has two identical forms (alleles) of a gene they aresaid to be homozygous (homo � same). If an individual hastwo different forms (alleles) of the gene, they are said to beheterozygous (hetero � different). Genes can be described asaltered or mutated, when a change has taken place, or

expressed, when the gene has an impact on the outward ap-pearance of an individual and/or the functioning of cells. Theobservable, outward expression of an individual’s entirephysical, biochemical, and physiologic makeup, as deter-mined by their genotype (alleles) and environmental factors,is referred to as phenotype. Phenotype may be expressed orobserved as curly or straight hair or the presentation of signsand symptoms of a disease.

Function and Distribution of GenesAlthough the function of more than 50% of the genes in the human genome is unknown, we do know that about 2% of thegenes give directions to parts of the cell for how to make pro-teins, what type of proteins to make, and how much of a pro-tein to make (HGP, 2004a). These protein-directing genes arevery important to life and functioning as a human being be-cause proteins are very specialized and perform a variety offunctions within the cell. These functions include transmittingmessages between cells, fighting infection, directing genes toturn “on” or “off,” forming structures, as well as sensing light,taste, and smell (Jegalian, 2000). Some gene activities changefrom moment to moment in response to tens of thousands of in-tra- and extracellular environmental signals (USDOE GenomePrograms, 2003). An example of this is the feedback mecha-nism that stimulates a cell to produce insulin after eating acandy bar. After eating, a gene on chromosome 11 directs pan-creatic cells to produce, modify, and secrete insulin. Althoughthe gene for producing insulin is present in all nucleated cellsof the body, it is only functional in insulin-secreting pancreaticcells (Guttmacher & Collins, 2002).

Mitochondrial GenesChromosomes in the cell nucleus are not the only site wheregenes reside. Several dozen that are involved in energy metab-olism are located in the cell mitochondria (the “powerhouse”of the cell). Mitochondria are concerned with energy produc-tion and metabolism. Some cells contain more mitochondriathan others, but each mitochondrion contains its own copies ofDNA identified as mitochondrial DNA (mtDNA). Because ovahave many mitochondria and sperm do not (most mitochondriaare located in the tail of the sperm that detaches after fertiliza-tion), mtDNA is primarily inherited from the mother. There-fore, mitochondrial genes and any diseases due to DNAalterations on those genes are transmitted through the motherin a matrilineal pattern. This pattern of inheritance is very dif-ferent from the pattern of inheritance of genes found in the nu-cleus of the cell (Guttmacher & Collins, 2002). Thus, anaffected female will pass the mtDNA mutation to all of herchildren; however, an affected male will not pass the mtDNAmutation to any of his children (Nussbaum et al., 2001). Signsand symptoms of conditions as a result of mitochondrial genealterations are primarily involved in high-energy tissues and or-gans such as skeletal muscles, liver, kidney, brain and nervecells, ears, eyes, endocrine system, and heart muscle. Symp-toms develop over years as unhealthy or dying cells are not re-placed. Hypertrophic cardiomyopathy, heart block, seizures,and deafness are also associated with mtDNA gene alterations(Nussbaum et al., 2001).

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Gene Alterations and DiseaseA protein will malfunction and in many cases cause disease ifany kind of alteration (mutation or change) is present in the or-der of the DNA sequence within a gene. These gene alterationscan be inherited from one or both parents or they can be acquired.Mutations inherited from a parent (hereditary mutations) are alsoknown as germline mutations because the mutation exists in thereproductive sperm or ova of the parent. Consequently, the DNAin every cell of that offspring will have the gene alteration andalso can be inherited from generation to generation.

The second kind of gene alteration is an acquired mutationor somatic mutation. These alterations occur in the DNA ofcells of the individual throughout their life. They can resultfrom errors during cell division (mitosis) or from environmen-tal influences such as radiation or toxins (National Institutes ofHealth [NIH], 1995).

Today, we know that gene alterations are responsible for ap-proximately 6000 hereditary diseases. However, different genealterations within a particular gene can result in a wide varietyof signs and symptoms. For example, the CFTR gene for cysticfibrosis is a very large gene located on chromosome 7. Morethan 800 different mutations of this gene have been reported tocause cystic fibrosis (Wine et al., 2001). The area of the CFTRgene that controls mucous production can have more than 300different gene alterations resulting in a variety of symptomsranging from mild, to severe, or no symptoms at all (NIH,1995). Gene alterations, not the genes themselves, cause ge-netic diseases and conditions.

Other situations where gene alterations cause illness anddisease are through gene interaction with the environment.These genes and conditions are referred to as multifactorial(Jegalian, 2000). Alterations in regulatory genes may also oc-cur. Regulatory genes play a part in maintaining homeostasis ornormal functioning. A regulatory gene mutation might lead tothe loss of expression of a gene, to unexpected expression in atissue in which it is usually silent, or a change in the time whena gene is usually expressed. An example of a regulatory genemutation associated with disease includes the insulin gene re-gion that increases the risk of type 1 diabetes (Guttmacher &Collins, 2002).

Gene Alterations That Decrease Risk of DiseaseAlthough it is common to associate gene mutations with dis-ease, it is important to remember that gene mutations can alsobe helpful and decrease the risk of disease. Gene alterationsand genetic variations may also have a protective role in the ex-pression of diseases. A common example is the protectivevalue of the gene alteration that causes sickle cell disease.Those individuals with this gene alteration have protectionagainst malaria. Another, less common example of a “protec-tive” gene alteration is the one on the receptor gene namedCCR5. This mutation consists of a deletion within the DNA se-quence. Persons who are homozygous for the CCR5 mutation(have two copies of the altered gene) are almost completely re-sistant to infection with HIV type I, and those who are het-erozygous for the deletion (have one copy of the altered gene)progress much slower from the stage of HIV infection to AIDS

(Guttmacher & Collins, 2002). As genomic research continues,more and more of these types of beneficial gene alterations willbe identified.

Single Nucleotide PolymorphismsSingle nucleotide polymorphisms, or SNPs (“snips”), are one-letter (base pair) variations in the DNA sequence that occur ingreater than 1% of the population. In all people, 99.9% of theDNA is identical; SNPs are responsible for differences amongindividuals. Polymorphisms are DNA sequences that havemany forms but give the genetic “directions” for the same thing.Most of these differences have no effect on the individual.Some cause subtle differences in numerous characteristics inappearance such as widow’s peak, tongue rolling, and attachedear lobes. Other SNPs, however, affect an individual’s risk forcertain diseases and have a major impact on how the individualresponds to environmental factors such as toxins, microbes, andmedications. Scientists are mapping these areas of SNPs in or-der to move to the next step of identifying the multiple genesthat are associated with diseases that are not caused by single-gene alterations, but the complex diseases caused by multiplegenes such as cancer, cardiovascular disease, some forms ofmental illness, and diabetes (HGP, 2004c; Jegalian, 2000).

PRINCIPLES OF INHERITANCEKnowledge of inheritance allows the nurse to not only offer andreinforce genetic information to clients and their families but alsoto assist them in managing their care and in making reproductivedecisions. The basic underlying principles of inheritance thatnurses can apply to inheritance risk assessment and teaching in-clude (1) all genes are paired, (2) only one gene of each pair istransmitted (passed on) to an offspring, and (3) one copy of eachgene in the offspring comes from the mother and the other copycomes from the father. Understanding the Mendelian patterns ofinheritance is made easier by relating these principles.

Mendelian Pattern of InheritanceConditions that are caused by a mutation or alteration of a sin-gle gene are known as monogenic or single-gene disorders.There are more than 6000 known single-gene disorders occur-ring in about 1 per 200 births (HGP, 2003). The most commongene alterations that result in genetic disorders are categorizedinto Mendelian inheritance patterns, because they are pre-dictably passed on from generation to generation followingMendel’s laws of inheritance. These single-gene mutations fol-low an autosomal dominant, autosomal recessive, X-linked re-cessive, or X-linked dominant inheritance pattern. The firstthree of these patterns are the most common. Modes of trans-mission or inheritance for thousands of conditions resultingfrom monogenic alterations have been identified (OnlineMendelian Inheritance in Man, 2003).

Recessive vs. Dominant DisordersThe distinction between recessive and dominant phenotypes ordisease presence (expression) is in the amount of gene product(usually proteins) from the unaltered (wild-type or normal)gene. When the individual is heterozygous (has one unaltered

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gene and one altered gene), the altered gene as well as the dis-ease is classified as recessive if half of the product producedfrom the unaltered gene is enough to maintain homeostasis andperform the expected function. Therefore, two altered genesmust be present to cause a diseased state. If the altered genecauses disease even though the unaltered gene is producing thegene product, then the altered gene as well as the disease isclassified as dominant (Nussbaum et al., 2001).

Autosomal DominantAutosomal dominant (AD) conditions are the result of an al-tered gene on any of the 22 autosomes or non–sex chromo-somes (Figure 8–3 ■). More than half of the known Mendelianconditions are autosomal dominant. In AD conditions, diseaseoccurs in spite of the fact that there exists one unaltered or nor-mal gene. Also, homozygous dominant conditions are gener-ally much more severe than heterozygous dominant conditionsand are often lethal. Because homozygous dominant conditionsare usually lethal and would result from both parents being af-fected, the nurse should consider an individual exhibiting anautosomal dominant condition as heterozygous. See Box 8–5for characteristics of an AD pattern of inheritance.

Autosomal RecessiveA gene or genetic condition is considered recessive when twocopies of altered genes are needed to express the condition. Au-tosomal recessive (AR) conditions are the result of an alteredgene on any of the 22 autosomes or non–sex chromosomes(Figure 8–4 ■). An individual with a recessive condition has in-herited one altered gene from his mother and one from his father.In most cases, neither of the parents is affected and, therefore,

each of the parents must have a single gene alteration on onechromosome of a pair and the normal, wild-type or unalteredform of the gene on the other chromosome. These parents wouldbe known as carriers of the condition and they do not usually ex-hibit any signs and symptoms of the condition. Because the genealteration occurs on a non–sex chromosome, both males and fe-males have an equal chance of inheriting the altered gene fromtheir parent. Generally, conditions that are autosomal recessiveare more severe and have an earlier onset than conditions withother patterns of inheritance. Most inborn errors in metabolism ormetabolic conditions are autosomal recessive. Many are enzymedefects and the functioning of the unaltered gene is sufficient to

AGametes

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Figure 8–3 ■ This Punnett square shows potential gene combi-nations (genotypes) and resulting phenotypes of children from par-ent genotypes with an autosomal dominant altered gene.Phenotypes are expressed (affected) when a male or female hasone copy of the gene alteration.

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Figure 8–4 ■ This Punnett square shows potential gene combi-nations (genotypes) and resulting phenotypes of children from par-ent genotypes with an autosomal recessive altered gene.Phenotypes are expressed (affected) when a male or female hastwo copies of the gene alteration.

BOX 8–5 Autosomal Dominant MendelianInheritance Characteristics

(Examples: neurofibromatosis, breast and ovarian cancer, autosomaldominant polycystic kidney disease, Marfan syndrome, Huntington disease,familial hypercholesterolemia)

When the nurse gathers a family history, the nurse should assessfor any of the following characteristics of autosomal dominant in-heritance:

1. Both males and females are affected.2. Males and females are usually affected in equal numbers.3. An affected child will have an affected parent and/or all

generations will have an affected individual (appearing as avertical pattern of affected individuals on the family pedigree).

4. Unaffected children of an affected parent will haveunaffected offspring.

5. A significant proportion of isolated cases are due to a newmutation.

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provide normal functioning in the person who is heterozygous orthe carrier of one copy of the altered gene (Lashley, 2005). SeeBox 8–6 for characteristics of an AR pattern of inheritance.

X-Linked RecessiveX-linked conditions are the result of an altered gene on the Xchromosome. Unlike the autosomes, the sex chromosome, X,

is unevenly distributed to males and females. The female hastwo X chromosomes and the male has only one. Thus, thefamily history and pattern of inheritance has a characteristicdistribution pattern among the males and females in the fam-ily (Figure 8–5 ■). Because the male has only one copy ofany gene on the X chromosome, it becomes the only copyavailable to give direction for those particular functions ofthese genes regardless of whether it is considered dominantor recessive in the female. Thus, if any of these genes are al-tered, an unaltered counterpart is not present to “override”the altered functioning gene.

The consequences of the altered gene on an X chromo-some will be expressed in all males. Females, on the otherhand, will have two copies and the unaltered gene generallycompensates for the altered gene, making the female a car-rier. The male receives his X chromosome from his motherand his Y chromosome from his father. The female offspringreceives an X chromosome from each of her parents. Thus, allaffected males will pass on the altered X chromosome to allof his daughters who will be carriers of the altered gene. Amale can never transmit an altered gene on the X chromo-some to his sons because the male will transmit only the Ychromosome to his sons. Because of these transmission pat-terns, the most commonly occurring transmission of an X-linked condition is through a female who is a carrier of analtered gene. See Box 8–7 for characteristics of an X-linkedrecessive pattern of inheritance.

BOX 8–6 Autosomal Recessive MendelianInheritance Characteristics

(Examples: hemochromatosis type 1, cystic fibrosis, phenylketonuria, sickle cellanemia)

When the nurse gathers a family history, the nurse should assessfor any of the following characteristics of autosomal recessive inheritance:

1. Both males and females are affected.2. Males and females are usually affected in equal numbers.3. An affected child will have an unaffected parent but may

have affected siblings (appearing as a horizontal pattern ofaffected individuals on the family pedigree).

4. The condition may appear to skip a generation.5. The parents of the affected child may be consanguineous

(close blood relatives).6. The family may be descendants of a certain ethnic group

that is known to have a more frequent occurrence of acertain genetic condition.

Gametes

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Potential gametecombinations

Potential gametecombinations

Figure 8–5 ■ These Punnett squares show potential gene combinations (genotypes) and resulting phenotypes of children from differ-ent parent genotypes with an X-linked recessive altered gene. Phenotypes are expressed (affected) in a male with only one copy of the genealteration and in a female with two copies of the altered gene.

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X-Linked DominantX-linked dominant conditions also exist but these conditionsare very rare. If a male is affected, the condition is severe andoften lethal. A family history of multiple male miscarriagesmay be a sign of an X-linked dominant condition.

Variability in Classic Mendelian Patternsof InheritanceAlong with understanding the classic Mendelian inheritancepatterns, several other concepts are also important for familiesto understand when the nurse is assisting clients with or at riskfor inheriting a genetic disorder. These include the followingexceptions or variations to the traditional Mendelian patterns ofinheritance.

PenetrancePenetrance is the probability that a gene will be expressed phe-notypically. It is an “all or none” concept in that, either the genewill be expressed (even if mildly expressed) or it will not be ex-pressed at all. Penetrance can be measured in the followingway. In a certain group of individuals with the same genotype,what percentage of them will exhibit at least some signs and/orsymptoms of the condition? If the number is less than 100%,then that condition is said to show reduced penetrance. For ex-ample, the gene alterations that cause achondroplasia exhibit100% penetrance and all individuals with one copy of the genealteration will exhibit signs and symptoms of the disease(Nussbaum et al., 2001).

New MutationWhen there is no previous history of a condition including evensubtle signs and symptoms of the disease in any other immedi-ate or distant family member, the disease may be caused by aspontaneous new mutation. This case is usually called de novomutation. New mutations of a gene are most frequently seen inautosomal dominant conditions because one copy of an alteredgene is all that is necessary to elicit a state of altered health. Au-tosomal dominant diseases known to have high mutation ratesinclude neurofibromatosis, achondroplasia (dwarfism), andMarfan syndrome. New mutations are also possible in autoso-mal recessive diseases although rarely expressed because twoaltered genes are necessary for signs and symptoms to appear.

Finally, new mutations are often seen in X-linked recessive dis-orders, such as hemophilia A, since the male with just one al-tered gene will demonstrate the disease.

AnticipationAnticipation is said to occur when successive generations of afamily exhibit more severe signs and symptoms of certain dis-eases and the disease often has an earlier onset. An example ismyotonic dystrophy type 1, an autosomal dominant conditioncharacterized by a range of signs and symptoms including my-otonia, muscle weakness, cataracts, and cardiac dysrhythmias.The congenital form is severe, causing mental retardation andmay be life threatening. Most children with this congenitalform of myotonic dystrophy have a mildly affected mother whomay not even be aware she has the disease (Nussbaum et al.,2001). The severity of the condition as well as the age of onsetis determined by the number of trinucleotide repeats. Trinu-cleotide repeats are short DNA sequences such as the CTG basesequence of the gene DMPK that are repeated to greater than2000 times, which results in alterations in the protein productsproduced by the gene and varying signs and symptoms.

Variable ExpressivityExpressivity is used to describe the severity of the gene ex-pression of the phenotype. When people with the same geneticmakeup (genotype) exhibit signs and/or symptoms with vary-ing degrees of severity the phenotype is described as variableexpression (Nussbaum et al., 2001).

Variable expression is common in the autosomal dominantcondition, neurofibromatosis. Although neurofibromatosis has100% penetrance, variable expressivity can occur within fam-ily members with each family member exhibiting a variety ofsigns and/or symptoms.

Multifactorial (Polygenic or Complex)DisordersMany birth defects such as cleft lip and palate, as well as manyadult-onset conditions such as cancer, mental illnesses, asthma,diabetes, obesity, heart disease, and Alzheimer’s disease, havea multifactorial cause. Multifactorial conditions occur as a re-sult of several gene (polygenic) variations, lifestyle, and envi-ronmental influences that work together. The polygenic conceptis illustrated with the multiple genes involved in an individual’ssusceptibility for breast cancer. These genes have been identi-fied on chromosomes 6, 11, 13, 14, 15, 17, and 22. Exactlywhich genes interrelate and how many environmental influ-ences are enough to cause the presentation of many of the com-mon complex diseases or conditions is not known. However, itis believed that by 2010, the major contributing genes for manycommon complex conditions will be identified (HGP, 2004a).

Multifactorial conditions accumulate in families but theseconditions do not follow the characteristic Mendelian pattern ofinheritance seen with single-gene conditions. Inheritable recur-rence risks vary in multifactorial conditions. With informationgathered from a family history, basic occurrence risks can be as-sessed for an individual. For instance, premature death in a first-degree relative, two affected first-degree relatives, and two

BOX 8–7 X-Linked Recessive MendelianInheritance Characteristics

(Examples: hemophilia A; Duchenne muscular dystrophy)

When the nurse gathers a family history, the nurse should assess forany of the following characteristics of X-linked recessive inheritance:

1. More males will be affected than females; rarely seen infemales.

2. An affected male will have all carrier daughters.3. There is no male-to-male inheritance.4. Affected males are related by carrier females.5. Females may report varying milder symptoms of the

condition.6. A new sporadic case could be due to a new mutation.

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second-degree maternal or paternal relatives with at least oneindividual having premature onset of the disease are all consid-ered high inheritance risks. Moderate risks include an individ-ual having a first-degree relative with late or unknown diseaseonset or two second-degree relatives from the same lineage withlate or unknown disease onset. An individual having no affectedrelatives or a negative family history, only one affected second-degree relative from one or both sides of the pedigree is consid-ered average or general population risk (Scheuner et al., 1997).

Recurrence risks refer to whether or not a condition will oc-cur again in subsequent pregnancies. Because a Mendelian pat-tern is not present, statistical percentages can be used torepresent the chance that parents have a condition that will occurin another child. The risk of recurrence is higher when more thanone family member is affected. The recurrence risk after the firstaffected child is 4.0%, whereas the recurrence risk after a secondaffected child increases to 10%. It is also known that the recur-rence risk increases with an increase in severity of the defect.

INTERDISCIPLINARY CAREMany health professionals work together in screening, diagno-sis, identification, and treatment of genetic disorders. The goalsof collaborative care are early diagnosis through testing and as-sessment, and development of an effective treatment plan,combined with psychosocial support to enhance coping and re-ferral to a genetic specialist when needed.

Genetic TestingGenetic testing may be used for a client’s clinical management,for making personal decisions, or for assisting in reproductivechoices. A genetic test is very different from other types of clin-ical tests. Genetic tests involve the analysis of DNA, RNA,chromosomes, and serum levels of specific enzymes or metabo-lites. Enzymes and metabolites are part of the protein productsthat genes produce. DNA, RNA, and/or chromosomes are veryunique for each individual and the results have personal, social,financial, and legal implications. Some genetic tests are diag-nostic, while others are predictive or inform the individual of anincreased risk of acquiring a disease or condition. A “positive”genetic test may indicate that the asymptomatic individual willdevelop a genetic condition, but a prediction of the onset orseverity of the condition cannot be made.

Complications also arise in client understanding because anegative test result cannot guarantee the disease or conditionmight not develop in the future, often because environmentalinfluences cannot be measured or controlled. Also, the genetictest may have only been able to detect the most common genemutations and not all of the disease-producing gene alterationsare known or available for inclusion in clinical testing. Clientsmay learn they will develop a genetic condition such as Hunt-ington disease, for which there is no treatment. Clients mayfind out through genetic testing that they are a carrier and theyhave unknowingly passed the altered disease-producing geneon to their children.

Finally, the implications of genetic test results are far reach-ing. While confidentiality and autonomy for the client always

are foremost for the nurse, the implications to the client’s chil-dren, grandchildren, siblings, and other extended family mem-bers who share a percentage of the same genes can be lifealtering. This information may be very confusing and very dif-ferent from how they have perceived health care in the past andhow they perceived the implications of a simple “blood test.”

TYPES OF GENETIC TESTS The nurse should understand thatgenetic tests can be classified into two categories: screeningand diagnostic. A positive screening genetic test result notifiesthe client of an increased risk or probability but must always beconfirmed by diagnostic testing. Screening genetic tests aremost commonly completed in prenatal, newborn, and carriercircumstances. In contrast, a diagnostic test can definitivelyvalidate or eliminate a genetic disorder in the symptomaticclient and then direct clinical management. Box 8–8 lists someof the positive and negative aspects of genetic testing.

Several categories of genetic tests included as subcategoriesof screening and diagnostic genetic tests follow:■ Newborn screening is carried out on large sections of the

newborn population and provides a means to identify chil-dren who have an increased risk for developing a genetic dis-ease such as phenylketonuria, sickle cell disease, or maplesyrup urine disease.

■ Carrier testing is completed on asymptomatic individualswho may be carriers of one copy of a gene alteration that canbe transmitted to future children in an autosomal recessive orX-linked pattern of inheritance. This may be part of a cou-ple’s premarriage or preconception planning if they belong toa particular ethnic group with known incidence to geneticdisorders such as sickle cell anemia and Tay-Sachs disease.It may be necessary to determine the exact gene mutation

BOX 8–8 Positive and Negative OutcomesRelated to Genetic Testing

Benefits of Genetic TestingProvide for:■ Early screening and preventive measures■ Future planning and life preparation■ Lifestyle adaptations■ Decreased confusion and anxiety■ Psychologic stress relief■ Reproductive choices■ Informed extended family members■ Early medical and/or surgical intervention■ Cost of medical follow-up reduced (if negative result)

Possible Negative Outcomes of Genetic Testing■ Survivor guilt■ Loss of identity■ No treatment may exist■ Employability and insurability affected■ Confusion about accessing health care and resources■ Risk for invasion of confidentiality and privacy■ Social stigmatization

Source: Data from Secretary’s Advisory Committee on Genetic Testing (SACGT),National Institutes of Health, 2000.

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from an affected family member prior to carrier testing. Thisis often completed through lineage analysis.

■ Preimplantation genetic diagnosis (PGD) involves the detec-tion of disease-causing gene alterations in human embryos justafter in vitro fertilization and before implantation in the uterus,thus providing an opportunity for preselection of unaffectedembryos for implantation. This type of genetic testing is mostoften used by parents who are both carriers of a single-gene re-cessive disorder and who wish to implant into the uterus onlythe embryo(s) without the disease-causing gene alteration.PGD is usually not covered by insurance, is very costly, and isavailable at only a small number of centers and for only a smallnumber of disorders (GeneTests, 2004). More recently it hasalso been used to determine tissue type for donation of tissuesuch as bone marrow to a sibling or parent (Javitt et al., 2004).

■ Predictive genetic testing is usually made available to theasymptomatic individual and includes both predispositionaland presymptomatic testing. A positive predispositional test-ing result will indicate there is an increased risk that the in-dividual might eventually develop the disease. Commonexamples include breast cancer and hereditary nonpolyposiscolorectal cancer. A presymptomatic test is performed whendevelopment of the disease is certain if the gene alteration ispresent. These tests are medically indicated when the seri-ousness and mortality of the disease can be reduced withknowledge of the gene alteration. An example of this wouldbe hereditary hemochromatosis or familial hypercholes-terolemia. Life planning and lifestyle choices can be influ-enced by predictive testing.

■ Other uses of genetic testing include organ transplantationtissue typing and pharmacogenetic testing, which involvespredicting or studying the client’s response to particularmedications (Javitt et al., 2004). For example, pharmacoge-netic testing has shown that individuals who haveAlzheimer’s disease and carry two copies of a particular al-tered gene do not respond well to a drug frequently used inthe treatment of Alzheimer’s disease. However, if the indi-vidual only has one copy of the altered gene, the drug is ef-fective in slowing the progression of the disease (Secretary’sAdvisory Committee on Genetic Testing, 2000a).

DIAGNOSING CHROMOSOMAL ALTERATIONS Microscopicexamination of chromosomes through a karyotype can revealchromosomal alterations such as chromosomal additions, dele-tions, gross breaks, and rearrangements or rejoinings (translo-cations) (USDOE Genome Programs, 2003). Among otherthings, these chromosomal alterations are responsible for manyforms of cancer and, more importantly, particular tumor types.Chromosomal diagnostic examination can be accomplishedwith a simple blood sample and skin or buccal cell sampling. Akaryotype is completed in a cytogenetics laboratory. Chromo-somes can be identified by their size and unique light and darkbanding patterns. The pairs of autosomal chromosomes arearranged from 1 to 22 according to each chromosome’s size,unique banding patterns, and centromere position. The sex chro-mosomes complete the picture, with the X chromosome(s) first,then theY chromosome (if present). The karyotype shows all of

the chromosome pairs lined up and positioned on a piece of pa-per allowing for visual chromosomal analysis. (See Figure 8–2earlier in this chapter.) The final report contains numerical datathat includes the total number of chromosomes present. If thereis an additional or deleted chromosome, it is identified with aplus (�) or minus (�) symbol. For example, the male individ-ual with 47, XY, �18 has 47 chromosomes (instead of the ex-pected number of 46) that include an additional chromosome 18.

DIAGNOSING GENE ALTERATIONS With the rapidly expandingadvances in technology and the identification of genes in the hu-man genome, the availability of genetic, DNA (gene)-basedtests has grown tremendously. Currently, more than 900 genetictests are available with more becoming available each day (US-DOE Genome Programs, 2003). DNA-based tests involve new,sophisticated technology that permits the examination of theDNA itself. Genetic testing that is DNA based can be obtainedfrom blood, bone marrow, amniotic fluid, fibroblast cells of theskin, or buccal cells from the mouth. Genetic testing includesdifferent types of DNA-based tests. The appropriate genetictests may be testing for a specific mutation. This would be usedif a family member was known to have a genetic condition andcould therefore be tested for that particular gene alteration. An-other way to examine DNA is by running a panel of mutations.This is done when there are a specific number of identified genesthat the majority of individuals with a genetic condition have, forinstance, a panel of the three mutations on the BRCA1 gene thatare common in the Ashkenazi Jewish population. A third type ofDNA-based test is a complete gene sequence (GeneTests, 2004).

QUALITY AND ACCURACY OF GENETIC TESTS Genetic nurseshave expressed concerns that genetic tests are becoming avail-able too quickly with no regulation of the companies that areoffering genetic tests. The quality, accuracy, and reliability ofgenetic test results are not measured against any common stan-dard. Individuals often make hard and irrevocable life-alteringdecisions after receiving test results so accuracy and reliabilityare essential. Also, in most cases, minimal or no education isprovided for the individual undergoing testing, nor is there anyquality counseling or follow-up after the results are given to theindividual. Genetic tests are often offered by laboratories be-fore the tests have been proven safe, effective, and practical.Because the majority of genetic conditions are rare, there is of-ten only one laboratory offering the genetic test that is needed.Recently, concerns have been voiced about “direct to con-sumer” genetic testing. Genetic tests are being offered at“walk-in” locations and also via the Internet. Individuals canreceive results of genetic tests in private without a physician’sorder and fear of discrimination, but also without education orknowledge of the implications of the test results.

Concerns also exist related to test validity, test sensitivityand specificity, the quality of the laboratory performing thetest, and the competence of the client’s healthcare provider tointerpret the test results. Test sensitivity refers to how specifi-cally the test identifies (positive test result) individuals who areaffected and/or who have the disease phenotype. A test with ahigh degree of sensitivity has very few false negatives andmany true positives. Test specificity refers to how specifically

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the test does not identify (negative test result) individuals whoare unaffected or do not have the disease phenotype. A test witha high degree of specificity has very few false positives(SACGT, 2000). The laboratory selected for the genetic testshould have a CLIA88 (Clinical Laboratories ImprovementAmendments of 1988) certification (Javitt et al., 2004).

NURSING CARE

The Role of the Nurse in Genetic TestingWith knowledge of available genetic tests and the many im-plications related to genetic testing, the nurse can assistclients as they weigh choices regarding genetic testing. Asconsumers of multimedia, clients often have unreliablesources for information related to genetic testing. They mayform many misconceptions about the types of genetic testsavailable and what information these different types of ge-netic tests are able and not able to provide. When managinggenetic information about genetic testing, the nurse must in-clude education for the individual and the family. Communi-cation with the client about genetic testing should include anassessment of the positive and negative outcomes of the test.Are there existing treatments for the condition being tested?Psychologic issues should also be emphasized. Who will beaffected by the test results? Will the test results be shared withextended family members?

The nurse is responsible for alerting clients of their right tomake an informed decision prior to any genetic testing withconsideration of the special circumstances arising from thefamily, culture, and community life. All genetic testing shouldbe voluntary and it is the nurse’s responsibility to ensure thatthe consent process includes discussion of the risks and bene-fits of the test, including any physical harm as well as potentialpsychologic and societal injury by stigmatization, discrimina-tion, and emotional stress (Beskow et al., 2001; InternationalSociety of Nurses in Genetics, 2000).

Above all, nurses have a responsibility to fully educateclients about the multiple issues related to genetic testing.Clients should engage in genetic testing with full knowledge,confidentiality, and autonomously. Informed consent may begiven verbally, although some laboratories require written con-sent. Prior to the testing, the client should have an idea of theprobability for a positive or negative result if one can be deter-mined by the client’s or family history (GeneTests, 2004). Todeliver the expected standard of care, it is imperative that thenurse include these issues when developing an educational planfor the client anticipating the use of genetic testing and as partof the informed consent process.

Ensuring Confidentiality and Privacy for Genetic TestingAlthough confidentiality and privacy are integral parts of de-livery of care for all nurses, this issue is of even more concernas it relates to genetic information. Results of genetic tests

can be far reaching and can affect employment and insuranceoptions. Will the results affect the client’s ability to obtainand/or maintain insurance coverage? Can an employer refuseto hire or promote an individual because of genetic testing re-sults? Can genetic information be released to the courts, mil-itary, schools, or adoption agencies? Would a client with aknown gene alteration for Huntington disease be offered acollege scholarship to the best law school? There is debateover whether genetic privacy is different from medical pri-vacy. The nurse should inform clients of their rights and re-sponsibility to know who will have access to the genetic testresults. Those providing the genetic tests must provide theclient with assurance that the results will be handled confi-dentially, and that there will be no access to the genetic infor-mation by a third party without written permission of theindividual being tested.

Results of genetic tests should only be communicated directly to the individual who gave the consent. No outsidegovernmental, employment, or insurance organizations shouldever have access to genetic test results without the written per-mission of clients. Clients should confirm how they will receivethe test results. Clients should ask who will have access to thetest results and what will happen to the DNA sample after thetest is completed. In the majority of cases, results of genetictests should not be shared with extended family members with-out written permission. Healthcare providers are legally liableto maintain that confidence. Exceptions to the individual’s pri-vacy may be made only when the individual refuses to informextended family members when a very high probability of irre-versible harm exists for the extended family member and in-forming the family member can prevent the harm (NationalHuman Genome Research Institute, 2005). Every effort shouldbe made to educate the individual about the benefits of inform-ing extended family members if applicable. Genetic testingshould ideally be accompanied by pretest and post-test coun-seling by genetic specialists or by another knowledgeablehealthcare provider.

Psychosocial IssuesAlthough family and individual anxiety may be decreased witha negative test result, potential problems do exist and the nursemust be prepared to address them. Concerns about carrier sta-tus may interfere with development of intimacy and interper-sonal relationships. Nonpaternity may be revealed throughgenetic testing. For example, the parents of a child born withan autosomal recessive condition will be considered carriers ofthe altered gene the majority of the time. To counsel the par-ents about future pregnancies, the parents would be tested toconfirm their genotype, and nonpaternity may become an is-sue. A positive test result may lead to feelings of unworthiness,confusion, anger, depression, and self-image disturbance. Sur-vivor guilt may affect adults with negative results if their sib-lings are positive. The individual carrying a gene alteration fora late-onset disease may have an increased tendency for riskybehaviors and may choose not to be a positive member ofsociety. Relatives of an individual affected with a genetic dis-

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order may be very frightened when they realize what their ownfuture might be (SACGT, 2000a). The individual who has in-herited an altered disease-producing gene may foster deep re-sentment toward the parent who carries the altered gene.Parents and older generations may feel tremendous guilt forpassing the altered gene to their children and grandchildren(Wertz et al., 1994).

Economic IssuesThe nurse should consider the cost of genetic tests, which canrange from hundreds to thousands of dollars, depending on thesize of the gene being tested. Most insurance companies do notcover genetic tests but if there is insurance coverage, the indi-vidual must weigh the cost of allowing the insurance companyto have access to the genetic information (HGP, 2005).

Genetic tests differ from routine medical tests in manyways. The risks and benefits of genetic testing are numerousand complicated. Nurses have an obligation to maintain theirknowledge regarding genetic testing to advocate for the clientas well as maintain ethical standards of care. Above all, nursesmust be able to recognize the limits of their expertise and howto refer a client to genetic specialists and additional resources.

AssessmentHealth Promotion and Health MaintenanceHealth promotion and health maintenance of the client areviewed as the foundations of all nursing care. However, mostindividuals do not know their complete genetic makeup. Someknow they carry an altered gene that causes a specific disease,but the majority of individuals do not know with certainty whattheir future health status will be. With no sure knowledge of ge-netic makeup or whether a certain alteration in health statuswill occur (heart disease, for example), healthy lifestyles arenot always a priority. Imagine, then, if people knew their sta-tistical risks for developing or inheriting disease by havingcomplete access to the types of genes in their cells? Healthpromotion and health maintenance teaching and nursing inter-ventions would be based on specific genes. The nurse couldprovide important, life-saving nutritional information to theirclients based on their specific risks, and clients then might bemore inclined to maintain a proper diet, give up their sedentarylifestyle, increase exercise, and decrease fast-food intake. Per-sonal lifestyle choices would become more personal and mon-itoring health might take on a new meaning.

With knowledge of genetic conditions, the nurse can ensurehealth teaching and early detection of complications from ge-netic conditions with emphasis on primary and secondary careinterventions. For example:■ A woman with a strong family history and/or mutations in

the BRCA1 and BRCA2 tumor suppressor genes should be-gin monthly self breast exams, and have screening clinicalbreast exams and mammographies at an earlier age than thegeneral population.

■ A man with a strong family history and/or mutations in theBRCA1 and BRCA2 tumor suppressor genes should report

any mass, tenderness, or swelling in the breast tissue andmaintain early screening for prostate cancer.

■ Aggressive colonoscopy screening every 1 to 2 years begin-ning at age 25 is important for the individual with a positivefamily history and/or mutations in the MLH1/MSH2 gene,which increases the risk for hereditary nonpolyposis col-orectal cancer.Clients receiving early intervention and health promotion-

focused care can live longer and with a much better quality oflife that those who do not. The nurse must be able to identifyboth community-based and genetic-based resources that areavailable to assist the client in strategies to support both healthpromotion and health maintenance activities.

By simply integrating into practice the genetic aspects of as-sessment, observation, and history gathering, the nurse can im-prove the standard of care delivered and have a very positiveimpact on the client. The nurse does not need to be a genetic ex-pert, but with heightened awareness, appropriate inquiries andreferrals to genetic specialists can be completed.

Client Intake and HistoryNurses can improve the standard of nursing care and have apositive impact on clients by integrating genetic concepts intotheir existing practice of inspection, observation, and historygathering. Nurses do not need to be genetic experts, but theyshould be able to recognize genetic features of physical assess-ment, basic patterns of inheritance, and predisposition to de-velopment of disease. As nurses integrate genetic concepts intotheir delivery of care, appropriate inquiries and referrals to ge-netic specialists can be completed.

Although family history has long been a part of nursing as-sessment, the relative importance of this assessment piece hasrecently increased as our knowledge of the interaction of genesand the environment has expanded. In phenotypically“healthy” individuals, an accurate and complete family historycan identify a single-gene (Mendelian) disorder or a mitochon-drial, multifactorial, or chromosomal inheritance pattern aswell as guide the prevention, diagnosis, and treatment of com-mon complex diseases such as cardiovascular disease and can-cer. A family history illustrates the interaction of genes and theenvironment for an individual and consequently provides a ba-sis for individualized disease prevention (Guttmacher et al.,2004). Although an individual’s inheritance risks from his orher genotype are nonmodifiable, knowledge of an individual’sincreased risk for chronic disease can influence lifestylechoices, clinical management, and sometimes risk reductionand prevention of the disease. Knowledge of a family historycan also guide diagnostic workups and clinical treatment(Guttmacher et al., 2004).

PedigreesA nurse should know how to take a family history, record thehistory in a pedigree, and think “genetically.” A pedigree is apictorial representation or diagram of the medical history of afamily. Multiple symbols are utilized to present this picture(Figure 8–6 ■) and the finished pedigree presents a family’smedical data and biologic relationship information at a glance

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and extended family members. Other sensitive issues includepregnancies conceived by technology, a history of suicides,drug or alcohol abuse, and same-sex relationships. Box 8–11lists ethical implications of genetic information.

Challenges inherent in recalling the family history includethe client’s inability to remember any conditions that may havebeen surgically repaired and then forgotten, or reporting condi-tions that may have been attributed incorrectly to other causes.Also, the family history may contain information previouslyunknown to extended family members. Reproductive decisionsmay have been made that were against the family’s religious orcultural beliefs. Both immediate and extended family membersmay be unaware of these “family skeletons” and the client maybe very reluctant to reveal this information (Bennett, 1999;Bowers, 2002).

Genetic Physical AssessmentAn assessment of newborns and children with a genetics focusof minor and major anomalies is essential. A minor anomaly ormalformation is an unusual or morphologic feature that in itselfis of no serious medical or cosmetic concern to the individualor family. A major anomaly is a serious structural defect at birththat may interfere with normal functioning of body systemsand may lead to a lifelong disability or even an early death(Aase, 1992).

Some children grow into adults whose physical featuresmay or may not have been recognized as potential links to ge-netic conditions. Anomalies that exist after a person is beyondexpected developmental and cognitive milestones may go un-noticed, but they may still be important. The nurse can pick upcues to genetic problems by inspecting the client and otherfamily members. If practical, nurses should ask to look at fam-ily photographs and examine them for common dysmorphicfeatures and family traits. Subjective assessment data can alsobe valuable. A client’s complaints of fatigue and joint pain mayindicate the onset of hereditary hemochromatosis. A physicalassessment that includes a genetics focus is important fornurses when caring for any age client. An undiagnosed geneticcondition may also have implications for reproductive deci-sions the client makes. However, genetic assessments and ge-netic referrals are important throughout the life span.

Nursing Diagnosis and InterventionsNurses are responsible for comprehensively delivering the cor-rect standard of care to clients, but at the same time being awareof the limitations of their own knowledge and expertise. In ad-dition to the continuous integration of genetic aspects intonurses’ assessments of family history and physical assessment,nurses are also responsible for carrying out interventions thatinclude initiating referrals to genetic specialists and deliveringcare to the individual or family in any of the following ways.Nursing diagnoses to consider include:■ Anticipatory Grieving■ Anxiety■ Disturbed Body Image■ Ineffective Coping■ Decisional Conflict

Figure 8–6 ■ Selected standardized symbols for use in drawinga pedigree.

Unaffected male

Unaffected female

Affected male

Identical twins

Siblings listed from left to rightby birth order

Fraternal twins

Biological parents

Affected female

Male carrier

Female carrier

Unaffected, sex unknown

Proband, propositusor index case

Multiple male individuals (number of sibling written inside symbol)

1 2 3

4

(Figure 8–7 ■). A pedigree provides the nurse, genetic coun-selor, or geneticist with a clear, visual representation of rela-tionships of affected individuals to the immediate and extendedfamily. It can identify other individuals in the family who mightbenefit from a genetic consultation. It also can identify a sin-gle-gene alteration pattern of inheritance or a cluster of multi-factorial conditions, and a referral and/or reproductive riskteaching for the individual and family can result. A family’slearning can be enhanced by the visual teaching contribution apedigree can provide and also clarify any inheritance misun-derstandings or misconceptions. Box 8–9 lists steps for creat-ing a family pedigree. If completed correctly and completely, apedigree allows all healthcare professionals working with theclient or family to quickly see what history and background in-formation has been collected (Box 8–10).

It is important to gather a three-generation family pedigreeeven if the nurse believes this is a first occasion of the condi-tion within a family (Figure 8-7). A condition without any iden-tifiable inheritance pattern on the pedigree may be due to a newmutation or variable expressivity. Throughout the process ofgathering family history assessment data, the nurse must re-member family confidentiality at all times: All information re-lated to a pedigree is confidential information. The history mayreveal sensitive details that include infertility problems, elec-tive termination of pregnancies, or nonpaternity. This informa-tion may not even be known by a current partner or immediate

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■ Interrupted Family Processes■ Ineffective Health Maintenance■ Deficient Knowledge■ Powerlessness■ Spiritual Distress

Genetic Referrals and CounselingAfter gathering assessment data that incorporates genetic con-cepts, the nurse is able to initiate a referral to genetic special-ists if there are indicators for a genetic referral (Box 8–12). Thenurse should provide the client with information about the ad-vantages of a referral to genetic specialists, and the disadvan-tages of not following through with the referral. The nurseshould inform the client that a genetic referral can provide in-formation and answer many questions they may have concern-ing genetic health. Questions regarding the conditions,inheritance, availability of treatment, as well as economic, in-surance, and future implications can be addressed.

Clients who are concerned about genetic disease may bene-fit from a genetic consultation whether or not genetic testing isavailable for that condition. Many people seek information andcoping strategies as much as they do test results. Referral of aclient with a suspected genetic problem to a geneticist, geneticclinical nurse specialist, or genetic clinic is an expected nurs-ing responsibility in the same way as referrals to a dietitian ora social worker. When in doubt, the nurse should contact the ad-vanced practice genetic clinical nurse, genetic counselor, or ge-neticist to discuss concerns.

CLIENT PREPARATION FOR GENETIC REFERRALS AND GENETIC COUNSELING Not knowing what to expectfrom a genetic referral is common, and the fear of the un-known may cause anxiety for the client. To facilitate the re-ferral to a genetic specialist, the nurse should educate theclient so that he or she knows what to expect during as wellas after a genetic evaluation.

1

1 3 42

2 3 4

Sibship line

ProbandIdentical twins

A

(A) A representative pedigree for a single character or genetic condition through three generations.(B) The most probable genotypes of each individual in the pedigree for an autosomal recessive condition, represented by AA, Aa, or aa.

5 6

65 7

1 2 43 5 6 7 10

8 9 10-13

4

Fraternal twins

8 9

1

1 3 42

2

aa AA or Aa

3 4

AA or Aa AA or Aa

B

5 6

AA AA

65 7

1 2 43 5 6 7 10

8 9 10-13

Aa Aa AaAa AA or AaAA or Aa AA or Aa AA AA AA

4

8 9

AAorAa

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Figure 8–7 ■ Sample three-generation pedigree.Source: Redrawn from Klug, W. S., & Cummings, M. R. (2003). Concepts of genetics (7th ed., p. 63). Upper Saddle River, NJ: Prentice Hall.

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Usually before the first genetic evaluation visit, the clientwill be contacted to provide a detailed medical and familyhistory and to make an appointment for genetic consultation.The client should be prepared to give as exact a family historyas possible so that a detailed three-generation pedigree can beconstructed. The client should be informed that a genetic con-sultation usually lasts several hours. During the appointment,

a genetic clinical nurse, genetic counselor, and/or a physicianwill perform an initial interview with the client. A geneticistwill examine the client in order to establish an accurate diag-nosis. Tests may be ordered. These may include chromosome(cytogenetic) analysis, DNA-based testing, x-rays, biopsy,biochemical tests, and linkage studies (Lashley, 2005). Afterthe exam and the completion of any applicable testing, the

BOX 8–9 Steps in Drawing a Pedigree

I. How to:1. Work in pencil.

a. Family historians often remember additional relativesand details only after questioning is almost completed.

II. Organization:1. Begin recording data in the middle of the sheet of paper.

a. Allow enough room for both the maternal and paternalsides of the family.

2. Use only standard pedigree symbols.a. For example, males are represented by squares and

females by a circle.3. The male individual in a couple is placed on the left of the

relationship line and the paternal side of the family alsogoes on the left-hand side of the paper.

III. Determining Family Relationships:1. The nurse should determine the relationships within the

family by asking questions such as:■ Do you have a partner or are you married?■ How many biologic brothers and sisters do you have?■ How many children do you have?■ Do all the children have the same biologic father?■ Do all the children share the same mother and father?

2. Referral to “the baby’s father or mother” can be helpfuluntil a relationship or marriage is established between theparents.

3. Referral to a “union” if marriage does not exist can alsohelp communication.

4. Determine if each individual is married, has children, signsand symptoms, etc., before continuing on to the nextindividual.

5. Always ask if there is any chance the mother could berelated to the father or if any other parents in the family areblood relatives.■ To determine consanguinity.

IV. Who Should or Should Not Be Included:1. To ensure accuracy, the pedigree should include the

parents, offspring, siblings, aunts, uncles, grandparents, andfirst cousins of the individual seeking counseling.

2. Detailed information about the spouses of the proband’sfamily can be omitted unless there is a history of somekind of disorder or condition.

3. Eliminating persons or any information that does notcontribute any valuable information can help keep thepedigree small and more manageable.

V. Recording the Family History:1. Determine the approximate size of the family.

2. Record the family’s ethnic background at the top of the page.

3. The initial drawing should begin with the proband, or theperson who is affected with the genetic condition.a. Usually the reason someone is seeking a genetic

referral.4. The proband is marked with an arrow on the pedigree.5. Draw and mark the symbols for the brothers and sister of

the proband. Draw the relationship line, the line of descent,marriage or union line, and symbols for parents of theproband.a. Repeat this step for any children of the proband or

children of the proband’s brothers and sisters.6. Children resulting from a mating (siblings) should be

recorded in descending order of their birth with oldestsibling on the left.

7. Continue with symbols for all immediate relatives drawnpreviously and then draw and mark symbols for paternalgrandparents and indicated relatives followed by the samefor the maternal grandparents and relatives.

8. A legend key should contain all of the correct symbols foreach indicated disease.

9. Record the age of onset of common and complex diseasesand/or conditions such as coronary heart disease; diabetesmellitus; hypertension; colon, breast, ovarian, orendometrial cancer; and stroke.

10. The pedigree should include at least three generations.a. Generations are symbolized by Roman numerals along

the left-hand side of the paper with the first generationmarker, I, at the top.

b. Each person in the generation should follow animaginary horizontal line from left to right.

11. The names of each individual (maiden names in case ofmarried women) and their dates of birth should beincluded along with half-siblings, pregnancy losses, stillbirths, previous marriages, and adopted children.

VI. Other:1. Consanguinity may be suspected if the historian repeatedly

gives the same last name on both sides of the family.a. Consanguinity can be confirmed by asking if any

relatives in the family have ever had a child together.VII. Completing the Pedigree:

1. When completed, the pedigree should be dated andsigned with the name, credentials, and position of theperson drawing it.

Source: Data from Bennett, R. L. (1999). The practical guide to the genetic family history. New York: Wiley-Liss.

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BOX 8–10 Specific Facts and Health Information to Include in a Pedigree

■ Age/birth date or year of birth■ Age of death (year, if known)■ Cause of death■ Age at diagnosis■ Full siblings versus half or step-siblings■ Pregnancy with gestational age (LMP) or estimated date of

delivery (EDD)■ Infertility versus no children by choice■ Pregnancy complications with gestational ages noted (e.g.,

6 wks, 32 wks)■ Miscarriage (SAB)

■ Stillbirth (SB)■ Pregnancy termination (TOP)■ Relevant health information (e.g., height and weight)■ Affected/unaffected status—define shading of symbols in a

legend key■ Ethnic background■ Consanguinity■ Date pedigree taken or updated■ Name of person who took pedigree and credentials■ Key or legend

geneticist and/or genetic counselor will discuss the findingswith the client and make recommendations. The discussionwill include the natural history of the condition, the inheri-tance patterns, the current preventive or treatment options,and the risks to the client and/or family. The visit will also in-clude opportunities for questions and answers as well as theassessment and evaluation of the client’s understanding. It istypical for the information retention of a client facing a newgenetic diagnosis to be very low. This makes it imperative forthe nurse to take advantage of opportunities to reinforce ge-netic concepts at a later time when the client is ready.

As the visit concludes, the client can expect appropriate re-ferrals to be made, discussion of available services or researchstudies, and possible scheduling of a follow-up visit. A sum-mary of the information is usually sent to the client and theclient’s healthcare provider will receive a report if requested bythe client.

Genetic healthcare providers present the client with informa-tion to promote informed decisions. They are also sensitive to theimportance of protecting the individual’s autonomy. A challengeduring any visit to a genetic specialist is providing nondirectivecounseling. Clients should be permitted to make decisions that arenot influenced by any biases or values from the nurse, counselor,or geneticist. Many clients are accustomed to practitioners andnurses providing direction and guidance in their decision making,and clients may be very uncomfortable with the nondirectionalapproach of the nurse. They may believe that the nurse or health-care provider is withholding very bad news. The nurse should dis-cuss the positives and negatives of each decision and present asmany options as possible through the use of therapeutic listeningand communication skills (Cunniff, 2001).

Client TeachingThe nurse must be aware of available genetic resources andparticipate in the education of genetic disorders as well ashealth promotion and prevention. Informing clients of what toexpect from a genetic referral as well as clarifying and/or rein-forcing information obtained during a genetic referral or fromgenetic test results is also important.

The cultural and religious beliefs and values of the clientmust be assessed by the nurse prior to teaching. Are the genealterations viewed as uncontrollable and believed to be occur-

ring secondary to cultural belief such as a stranger looking atthe client? Or, are the gene alterations considered a “punish-ment”? A client’s readiness to learn can be influenced by cul-tural or religious beliefs and values. Obtaining educationalmaterials in the native language of the client will also help fa-cilitate the teaching-learning experience.

The nurse must be aware of common inheritance miscon-ceptions such as a client’s belief that with a 25% recurrencerisk, after one child is affected, the next three children will beunaffected or with a 50% recurrence risk, every other child willbe affected. The recurrence risk for each pregnancy should becontinually stressed by the nurse. Clients often believe that afamily member has inherited the genetic condition becausethey look or “take after” a relative with a genetic condition.When new gene alterations or mutations are discussed, clientswill often exhibit surprise because no one else in the family hasthe condition so they perceive that the trait or condition cannotpossibly be inherited (Bennett, 1999). Helping clients to un-derstand these genetic concepts is fundamental to deliveringthe standard of genetic nursing care.

Psychosocial CareTo meet the client’s psychosocial needs, the nurse shouldidentify the client’s expectations and needs as well as theclient’s cultural, spiritual, value, and belief system. Fromwhere does the client receive strength? Denial of the geneticdiagnosis is common and nurses must be aware of the client’sstate of acceptance. Individuals often will not believe that achronic genetic condition exists. Nurses must also providecare to help alleviate any anxiety and/or guilt in the client.Anxiety of the unknown is common when awaiting diagnosisor test results, but individuals also experience anxiety fromnot understanding the future implications of a confirmed ge-netic disease. Guilt may be associated with knowledge of theexistence of a genetic condition in a family. The nurse mustsupport clients as they contemplate telling extended familymembers, friends, and neighbors about a confirmed diagno-sis. Clients often do not want to tell extended family mem-bers until they are ready. The nurse should encourage opendiscussions and the expression of fears and concerns. Guiltand shame are very common as a client deals with the lossof the expectation and dream of a healthy, productive life.

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Reinforce to clients that genetic alterations are caused bychanges within a gene and not by superstitions related to sinor other cultural beliefs. However, it is important to remem-ber that everyone has superstitions or beliefs and the nursemust remain nonjudgmental. As mothers, fathers, siblings,and extended family members provide continuous care forthe client with a genetic condition, depression can result. De-pression also can occur in the individual with the chroniccondition. The nurse must maintain awareness of the possi-bility of depression and be proactive in obtaining support forthe client or family.

The nurse also is responsible for assessing the client’s cop-ing mechanisms as well as available family, spiritual, cultural,and community support systems. Genetic conditions cancause a permanent strain on family dynamics and relation-ships. The nurse may need to help the client reaffirm his or her

self-worth and value (Lashley, 2005). If seen in an academicsetting, clients may feel they are part of a “production line”even though they are present for a very private problem (Cun-niff, 2001). Nurses must be sensitive to these perceptions,provide open communication, and encourage discussion offeelings. Growth and development and meeting adult devel-opmental milestones can be altered by actual or potential ge-netic disorders. Especially unique is the potential or actualinheritance of a late-onset condition such as Huntington dis-ease. The client with this altered gene may not meet any of thedevelopmental tasks in moving through adulthood. Shouldthe client get married, attend college, save money, or worryabout future? The nurse must identify the impact of geneticknowledge on activities of daily living but also movementthrough developmental milestones. Both client and familystrengths need to be identified.

Informed Consent■ Are all individuals receiving true informed consent and do they

understand all of the consequences of agreeing to even asimple blood test in the doctor’s office that may reveal adiagnosis or increased risk for a genetic condition?

Health and Life Insurance■ Should insurance companies have access to genetic test results?■ Should medical insurance costs be higher for persons with a

known gene disease-producing alteration?■ Should medical insurance costs be higher for persons with a

known increased risk for disease because of any gene alteration?■ Should medical insurance costs be higher for persons with

known increased risk for disease because of any gene alterationif they make unhealthy lifestyle choices and do nothing to lowertheir risk?

■ Should the individual be covered by medical insurance at all?■ Should individuals pay higher costs if they have children?■ Should individuals be required to have a large life insurance

policy to financially protect their families?

Financial■ Should the child be eligible for government grants or any

scholarship money?■ Should society be expected to financially support children

through government programs or private insurance?■ What is the motivation to save money for the future?

Employment■ Should an employer have access to an individual’s genetic

profile?■ Should a young adult be hired even though she/he will burden

the company with multiple sick days, higher insurance financialsupport, etc.?

■ Should the individual receive promotional opportunities andincreased job responsibilities if the employer knows there will bea great deal of lost work days?

■ Will the individual’s productivity be affected by the geneticcondition?

BOX 8–11 Ethical Implications of Genetic Information

The nurse must consider the enormity of the ethical issues facing allfamilies who have knowledge of their genetic makeup. The ethicalissues a nurse may have to discuss with the client are numerous. Afew of the issues are listed below.

Access to Information■ Who should have access to personal genetic information, and

how will it be used?■ Do insurers, employers, courts, law enforcement, schools,

universities, adoption agencies, and the military have a right toaccess this information?

Self-Perception■ How does personal genetic information affect an individual’s

perception of self?■ How does personal genetic information affect society’s

perceptions of that individual?■ How does personal genetic information affect an individual’s

cultural identity?■ How is self-identity and self-worth affected by a confirmed

genetic risk or condition?

Family Roles and Relationships■ Should an individual be tested for an autosomal dominant

condition if the siblings and/or parents are opposed to knowingif they, themselves, have the altered gene?

■ Should potential mates have genetic information?■ Should two people with increased genetic risk be prohibited

from having children?■ Should a child be tested?■ Should the father be told if genetic testing and/or genetic

counseling reveals nonpaternity?■ Should adoption records contain a complete genetic history of

the biologic parents?■ Is there an obligation to tell other family members if an altered

gene that demands a change in lifestyle (nutrition, exercise,smoking, etc.) is diagnosed?

■ Is there an obligation to tell other family members if an alteredgene that causes early debilitation and/or death is diagnosed?

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The nurse can refer the client to a support group. Howeverit is important to have permission from the client if the nurse isproviding a support group with the client’s name and contactinformation.

Another key role for the nurse is to help clients with the of-ten difficult task of communicating genetic information such asinheritance patterns to extended family members. Cultural val-ues of autonomy and privacy are impacted when a client mustconsider whether to communicate genetic information to ex-tended family members who may also carry the altered gene.The history of a genetic alteration that may or may not causedisease can be extensive within a family, affecting multiplefamily members. Family members often have difficulty under-standing that some genetic conditions have variable expressiv-ity. Members of the extended family often are shocked and feela profound sense of guilt that they are the one who has carriedthe gene alteration that caused their loved one to have a geneticcondition.

Careful self-assessment of feelings is essential for the nurse.The nurse must continually advocate for clients and supporttheir decisions even if the decisions contradict the nurse’s ownideals and morals. Coping with genetic revelations and makinggenetic-related treatment decisions are difficult activities foreveryone. The nurse must remember that clients will need re-sources and support, and also help in gathering informationabout reproductive options.

EvaluationExpected outcomes of delivering nursing care with a geneticfocus include:■ The client will make informed and voluntary decisions re-

lated to genetic health issues.■ The client will accurately identify:

■ Basic genetic concepts and simple inheritance risk probabilities■ What to expect from a genetic referral.■ The influence of genetic factors in health promotion and

health maintenance.■ Differences between medical and genetic tests.■ Social, legal and ethical issues related to genetic testing.

VISIONS FOR THE FUTURENurses are often the primary caregivers to whom clients turn forinformation, guidance, and clarification of ideas. This nursingrole is essential not only in providing direct nursing care but asa member of the community. As more information about the ge-netic revolution becomes available to consumers—in areas suchas pharmacogenomics, gene transfer, ethics, genetic engineer-ing, and stem cell research—the role of nurses remains not onlyvital but grows enormously. Nurses should remain educated, in-formed, knowledgeable, and ready to discuss trends and changeswith clients and their families.

BOX 8–12 Adult Indicators for a Referral to a Genetic Specialist

Adult History Assessment Data Concerns■ Several closely related individuals affected with the same or

related conditions:■ Breast and ovarian cancer■ Colon and endometrial cancer■ Diabetes■ Hypertension■ Coronary heart disease■ Thyroid cancer■ Colon polyps

■ A common disorder with earlier age of onset than typical(increase concern if it occurs in more than one family member):■ Breast cancer: < 45–50 years of age or premenopausal■ Colon cancer: < 45–50 years of age■ Prostate cancer: < 45–60 years of age■ Vision loss: < 55 years of age■ Hearing loss: < 50–60 years of age■ Dementia: < 60 years of age■ Heart disease: < 40–60 years of age■ Stroke: < 60 years of age

■ A sudden or unexpected death in someone who “seemed”healthy

■ Renal disease■ Asthma■ Suicides

An Individual with:■ Two or more conditions■ A medical condition and dysmorphic features■ Developmental delay with dysmorphic features and/or physical

birth anomalies■ Learning disabilities■ Behavioral problems■ Unexplained:

■ Movement disorders■ Seizures■ Hypotonia■ Ataxia■ Infertility

■ Disproportionate tall or short stature■ Proportionate short stature with dysmorphic features■ Atypical sexual development■ Premature ovarian failure

Source: American Medical Association. (2004). Family medical history in disease prevention. Retrieved March 12, 2005, from http://www.ama-assn.org/go/familyhistory

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EXPLORE MEDIALINKPrentice Hall Nursing MediaLink DVD-ROM

Audio GlossaryNCLEX-RN® Review

AnimationHuman Genome Project

COMPANION WEBSITE www.prenhall.com/lemoneAudio GlossaryNCLEX-RN® ReviewCare Plan Activity: Genetic Implications of Adult Health

Nursing CareCase Study: Genetic ImplicationsMediaLink Application: Create and Analyze a Family PedigreeLinks to Resources

CHAPTER HIGHLIGHTS■ Nurses are responsible for basic genetic knowledge and delivering

the expected standard of genetic nursing care.■ When cell division does not occur as expected, chromosomal

alterations on the autosomes or sex chromosomes can result.■ Chromosomal alterations can be seen in a human karyotype.■ Protein-directing genes are very important to life and functioning

as a human being because proteins are very specialized andperform a variety of functions within the cell.

■ Different forms of genes are alleles.■ An individual may be identified as heterozygous or homozygous

for a single gene.■ Some gene alterations cause disease and some are protective

from disease.■ Mitochondrial gene alterations are inherited from the mother and

are primarily involved in high-energy organs such as skeletalmuscles, brain, and heart muscle.

■ Multifactorial inheritance does not follow Mendelian inheritancepatterns.

■ Genetic healthcare providers present the individual and their familywith information to promote informed decisions.

■ Many types of genetic tests are available and they differ fromroutine medical tests.

■ All genetic tests have special considerations related to social,financial, ethical, and legal implications.

■ Basic genetic nursing care involves family risk assessment througha detailed family history, drawing a three-generation pedigree, andintegrating genetic concepts into a physical assessment.

■ Basic genetic nursing involves initiating a referral to a geneticspecialist.

■ Knowledge of the principles of inheritance allows the nurse to notonly offer and reinforce genetic information to clients and theirfamilies but also to assist them in managing their care and inmaking reproductive decisions.

■ Genetic concepts can be applied to health promotion and healthmaintenance.

■ The nurse must be aware of the social, ethical, cultural, andspiritual issues related to the delivery of genetic nursing care.

TEST YOURSELF NCLEX-RN® REVIEW1 The client is discussing the inheritance of an autosomal dominant

trait. The client has the condition and the client’s wife does not.They have one child without the condition. The nurse would becorrect in explaining to the client that he is most likely whichgenotype?1. FF2. Ff3. ff4. XfY

2 The male client diagnosed with Fabry disease is admitted to the unit.Which statement made by the client would indicate to the nursethat the client understands Mendelian inheritance concepts? “I havethe disease because . . .” (Select all that apply.)1. my mother had Fabry and my father did not.”2. my father’s mother had Fabry disease.”3. my grandmother’s brother had Fabry disease.”4. my father has Fabry disease.”

3 The nurse is providing information regarding genetic testing to acouple who believe they are carriers of an autosomal recessivegene alteration. Which statement by the nurse is appropriate?1. “If both of you are carriers, all of your sons will be affected

and all of your daughters will be carriers.”2. “Chromosomal studies will reveal if you are actually a carrier.”3. “Newborn screening will reveal if your child is affected.”4. “During the genetic evaluation, you will be asked to provide at

least a three-generation family history.”

4 The nurse knows that which assessment data obtained during afamily history may suggest a genetic condition or inheritedsusceptibility to a common disease? (Select all that apply.)1. breast cancer at age 332. a sibling who died unexpectedly while playing basketball at

age 663. colon polyps in four third-degree relatives4. a brother’s unexplained infertility

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5 When analyzing a family pedigree, the nurse notes the pedigreedemonstrates that successive generations contain affectedindividuals, both males and females are affected, and there is nofather-to-offspring inheritance. What is the most likely pattern ofinheritance?1. autosomal dominant2. autosomal recessive3. x-linked recessive4. multifactorial5. mitochondrial

6 When the nurse is developing a teaching plan, which statement isa correct rationale regarding the health promotion and healthmaintenance benefits from an assessment of family history?(Select all that apply.)1. Clinical treatment options can be more focused.2. Prophylactic treatments can be started early.3. Specific diet, exercise regimen, and genotype can be

determined.4. Single-gene alteration can be diagnosed.

7 The nurse is recording a family pedigree. Which would be correctto include in drawing the pedigree?1. Detailed information is important for all persons recorded on

the pedigree.2. The maternal side of the family should be placed on the left

of the page.3. The proband is marked with an arrow and a “P.”4. Two generations should be recorded and labeled with Roman

numerals.

8 The nurse would consider which assessment finding(s) as minoranomalies? (Select all that apply.)1. café au lait spots2. ear pits3. atrial septal defect (ASD)4. hypertelorism

9 Which are appropriate concepts for the nurse to include whendeveloping a teaching plan for the client prior to genetic testing?(Select all that apply.)1. Predispositional genetic tests are medically indicated when

the seriousness and mortality of the disease can be reducedwith knowledge of the gene alteration.

2. To meet quality assurance, laboratories should hold a CLIA88certification.

3. A mutation panel contains the most common genealterations but it may not include all of the disease-causingmutations.

4. Family members affected by genetic test results have a legalright to the test results.

10 The client asks the nurse if a genetic referral is necessary. Whichinformation would be appropriate for the nurse to provide? Mostlikely genetic specialists will: (Select all that apply.)1. provide direction for important decision making.2. complete chromosomal studies.3. ask to see photographs of relatives.4. provide information about the natural history of the condition.

See Test Yourself answers in Appendix C.

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